.header {
    background-color: #2c3e50;
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
    position: sticky;
    top: 0;
    z-index: 1000;
}

.nav {
    max-width: 1000px;
    margin: 0 auto;
    padding: 0 20px;
    height: 60px;
    display: flex;
    align-items: center;
}

.nav-left {
    display: flex;
    align-items: center;
}

.nav-link {
    color: #ffffff;
    text-decoration: none;
    font-weight: 500;
    font-size: 16px;
    padding: 8px 16px;
    border-radius: 4px;
    transition: background-color 0.3s;
}

.nav-link:hover {
    background-color: #34495e;
}

/*背景設定*/
body {
    background-color: #f5f5f5;
}

/*共通セクション*/
.action-section {
    background: white;
    margin-bottom: 20px;
    padding: 25px;
    border-radius: 8px;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
}